Cementitious veneer and laminate material

ABSTRACT

A cementitious veneer and laminate composition is provided. The cementitious laminate composition includes a substrate, a primer layer applied to the substrate, the primer layer comprising a mixture of polyvinyl alcohol catalyst, Portland cement, and sand; and a cementitious veneer layer applied to the primer layer, the veneer layer comprising a mixture of magnesium sulfate, filler, magnesium oxide, gypsum cement, and polyvinyl alcohol catalyst. The polyvinyl alcohol catalyst comprises a mixture of polyvinyl alcohol fibers dissolved in water and mixed with butylene carbonate. The veneer layer is applied to the substrate and primer layer by means including spraying and manual spreading. The veneer layer can be ornamentally manipulated either before or after curing of the veneer layer. The veneer composition can be formed into laminated tiles or panels for use in building applications.

FIELD OF THE INVENTION

The present invention relates to decorative surface coatings and, moreparticularly, to durable surface coatings that incorporate acementitious veneer.

DESCRIPTION OF RELATED ART

Traditional building materials, such as stone, cement, brick, and tileobjects have long been valued for both their structural integrity andaesthetic appearance. Since these materials are typically heavy andcumbersome, special measures must often be undertaken to ensure thatobjects and structures made of such materials are properly supported.Unfortunately, not all existing buildings or other structures arecapable of bearing the weight of such objects. Indeed, costly reinforcedframes, reinforced flooring, and so on, are frequently required toensure such support. In some cases, these structures may impose verysignificant costs and require overly complicated building techniques.

In addition, the material cost of stone, cement, brick, and tile(hereinafter collectively referred to as “masonry”) can also beexpensive. Consequently, economical lighter weight surface coatings thatsimulate the appearance of masonry have been used to enhance theappearance of both utilitarian and decorative objects.

FIG. 1 is a perspective view of an uncoated surface 10 according to theprior art. It is well known in the prior art to apply a surface coatingor covering to such a surface, for both structural and aestheticpurposes. Examples of common surface coatings that have been made tosimulate the appearance of masonry include vinyl coverings, fabrics,paints, plaster, plastics (e.g., Corian™), and other manufacturedmaterials, such as Formica™. Generally, however, these materials havevarious disadvantages. Vinyl floor and wall coverings usually provide arubbery appearance and are typically recognizable as imitations. Fabricsand paint may be printed or applied in such manner to give a superficialappearance of masonry, but since these materials are quite different ascompared to masonry, they are also often easily detectable asimitations. Moreover, fabrics and paint are relatively delicate and donot withstand a great deal of wear and tear. Plaster may provide abetter approximation of masonry than the above materials, but plaster isrelatively soft, lacks durability and is subject to chipping andcracking. Sheet rock, plaster and gypsum products are also susceptibleto black mold growth that often results when the paper backing used forsuch wallboard products comes into prolonged contact with water ormoisture.

The search for lightweight durable materials that give the appearance ofmasonry has lead to the development of masonry-like coatings that may beapplied to suitable foundation materials such as wood, metal, cementfiber boards, or polymeric objects. For example, a method and apparatusfor producing an ornamental concrete surface is described in U.S. Pat.No. 5,502,941. As described therein, an ornamental coating which appearsas brick or flagstone may consist of a waterproof sub-base of epoxyresin and an elastomeric sealant covered with fiberglass webbing. Afirst mortar layer of cement, sand, color pigment and aqueous solutionof adhesive resin is then sprayed or troweled on. When the first layercures, a template having a pattern of grout lines is placed over thefirst layer and a second mortar layer having the same composition as thefirst layer is applied except that a contrasting color is used to givethe appearance of grouted brick or flagstones. The ratio of cement tosand is given as fifty-fifty with solution of acrylic resin varying fromone and one-half to two gallons per 46 pounds bag of dry cement/sandmix.

In U.S. Pat. No. 5,447,752, a method is described for making adecorative cementitious pattern on a surface. The surface coatingcomposition is described as comprising cement, sand, a polymer binder,and water. The binder is an acrylic latex polymer, such as styrenebutadiene in water. Cement is mixed with sand (30%-40% cement) to form amixture which is combined with the binder solution in an amount rangingfrom two to three gallons binder solution to 100 pounds cement/sand. Thepreexisting surface is etched with muriatic acid, brushed and spraywashed. A template having a desired pattern is placed on the surface anda layer of the surface coating composition is applied into openings inthe template by spraying or by manual spreading.

U.S. Pat. No. 3,592,724 describes a cementitious laminate of sulfonatedpolymers useful for making walls, floors, ceilings and plasterboardshaving improved water vapor impermeability. As described therein, thelaminates consist essentially of a surface sulfonated water insolubleresinous film and an inorganic cementitious material adhering to atleast one surface of the film. In one aspect, hydraulic cement isplastered on a wall and sulfonated film is adhered to the plasteredwall. The laminated wall may be finished with a coat of gypsum plaster.

In general, present known techniques for producing cementitiouslaminates present certain disadvantages. These include expensive andcomplicated processes, and/or the production of laminates that are heavyand difficult to use and install. A further disadvantage of presenttechniques is that the laminates produced do not feature surfaces thatare sufficiently scratch-resistant, fireproof, or waterproof enough formany industrial or home use environments. Also, available thin cement orconcrete veneers are inherently brittle due to the use of relativelylarge-size aggregates; the use of polymers to counteract the problem ofbrittleness and cracking due to these aggregates often results in aveneer that is overly plastic or resin-like in appearance. A yet furtherdisadvantage associated with present cement and concrete manufacturingmethods is that they are generally very polluting and impose asignificant impact on the environment.

It is therefore desirable to provide a process that produces economicallightweight and durable coatings, which can be used to simulate theappearance and function of masonry.

It is further desirable to produce cementitious laminates and veneersthat utilize inexpensive and preferably recycled materials that satisfypresent environmental and sustainability concerns.

It is yet further desirable to produce a cementitious veneer thatfeatures the use of micro-aggregates to prevent the problem ofbrittleness associated with present thin cement veneers.

It is also desirable to produce a cementitious veneer that is readilyformable into lightweight transportable panels for use in buildingapplications.

SUMMARY OF THE INVENTION

A cementitious laminate composition, and method for applying saidcomposition are provided. The cementitious laminate composition includesa substrate, a primer layer applied to the substrate, the primer layercomprising a mixture of polyvinyl alcohol catalyst, Portland cement, andsand; and a veneer layer applied to the primer layer, the veneer layercomprising a mixture of magnesium sulfate, Fillite, magnesium oxide,gypsum cement, and polyvinyl alcohol catalyst. The polyvinyl alcoholcatalyst in the primer and veneer layers comprises a mixture ofpolyvinyl alcohol fibers dissolved in water and mixed with butylenecarbonate. The primer layer is applied to the substrate to provide anadhesive surface that bonds the veneer layer to the substrate. Theveneer layer is applied to the substrate and primer layer by meansincluding spraying and manual spreading. The veneer layer can beornamentally manipulated either before or after curing. The cementitiouslaminate composition can be provided as a kit including the substancesused to form the primer and veneer layers. The veneer composition can beformed into laminated tiles or panels for use in building applications.

Other objects, features, and advantages of the present invention will beapparent from the accompanying drawings and from the detaileddescription that follows below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and notlimitation in the figures of the accompanying drawings, in which likereferences indicate similar elements, and in which:

FIG. 1 is a perspective view of an uncoated substrate surface accordingto the prior art;

FIG. 2 is a perspective view of a substrate surface coated with a primerlayer for a cementitious laminate according to one embodiment of theinvention;

FIG. 3 is a perspective view of a decorative cementitious veneer layerapplied to a primer layer and substrate according to one embodiment ofthe invention;

FIG. 4 is a perspective view of a decorative cementitious veneerlaminate, according to a first alternative embodiment of the presentinvention; and

FIG. 5 is a perspective view of a decorative cementitious veneerlaminate, according to a second alternative embodiment of the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Embodiments of the present invention provide a cementitious,masonry-like veneer surface that is economical, lightweight, highlydurable and versatile. The cementitious veneer can be readily providedin a variety of colors and textures. In addition, it can also be shaped,molded, sanded and/or polished to achieve many desired appearances.

Embodiments of the invention also provide an accurate simulation of theappearance, feel and durability of natural masonry. The cementitiousveneer of the present invention has sufficient strength to resistchipping, gouging and cracking, but is light enough to cover desiredobjects without requiring additional support. In addition, thecementitious veneer described herein features advantageous heat andwater resistance characteristics, making it suitable for use in avariety of different building and finishing applications.

In a preferred embodiment, the cementitious laminate material describedherein comprises a substrate layer coated with an adhesion or primerlayer, onto which is applied a cementitious veneer layer. The substrateprovides a firm backing structure for the cementitious veneer, and theadhesion layer helps adhere the cementitious veneer layer to thesubstrate. The cementitious veneer layer comprises the outer layer ofthe cementitious laminate material that features the appearance of anatural masonry material.

Substrate Layer

The cementitious veneer can be applied to cover any appropriateunderlying surface on which a masonry-like finish is desired. Theunderlying support surface comprises a substrate, which serves as thebase building material upon which first (primer) and second(cementitious veneer) layers are placed, and in general can be of anyshape, such as flat or curved. For optimum results, the substrate shouldbe a stiff, non-breathable material. FIG. 2 illustrates a substratelayer 10 upon which a first layer 20 is applied.

In a preferred embodiment of the present invention, the substrate 10comprises a honeycomb structural cardboard, such as Hexacomb™ made byPactiv Corporation. This provides the desired characteristics oflightness, flexibility, strength, and easy installation. Depending uponthe honeycomb size, the strength rating of this substrate can range from8 psi (pounds per square inch) to 60 psi. Other fiber boards can also beused for the substrate, including cement fiberboards, such as plycem™made by U.S. Architectural Products, Inc., and Hardi™ Backboard made byHardi Corporation.

Other suitable substrate materials include metal, masonry, fiberglass,gypsum board, Masonite®, plastics, ceramic, cement fiber board, othertypes of fiber boards, and other common building materials. Wood canalso be used as a substrate material, and would preferably be anon-bending hardwood that exhibits satisfactory non-breathingcharacteristics.

Adhesion/Primer Coat Layer

As shown in FIG. 2, a first base layer 20 is applied to the underlyingsubstrate surface 10. For application of this layer, the underlyingsubstrate surface should be clean and dry. To provide an optimal bondingsurface, the underlying surface can be prepared by etching or sanding.Any method of such surface preparation for bonding known to those withskill in the art may be used herein.

This first base layer 20 is an adhesion layer, also referred to as a“primer layer” or “scratch coat” that acts as an undercoating to helpbond the ultimate cementitious veneer layer to the substrate. In oneembodiment of the present invention, the primer layer comprises amixture of polyvinyl alcohol (PVA) catalyst, Portland cement, and resincoated sand. The mixture is produced by combining, on a volume basis,1.5% to 3.6% Portland cement, 68% to 75% resin coated sand, and 29% to30% polyvinyl alcohol polymer mixed with butylene carbonate in a ratioof 16:1, respectively. The polyvinyl alcohol polymer is produced bydissolving an amount of polyvinyl alcohol fibers in water in anapproximate ratio of one part PVA fibers to 16 parts water. When mixedwith butylene carbonate, the polyvinyl alcohol polymer produces thepolyvinyl alcohol catalyst (PVA catalyst).

An exemplary formulation which provides an illustration of the relativepercentages of these ingredients in the adhesion coat layer is providedas follows:

-   -   8 oz. of polyvinyl alcohol polymer mixed 16:1 with butylene        carbonate where the PVA polymer is produced by dissolving 30-40        grams of PVA fiber in 16-20 oz. of distilled water    -   0.40 to 0.80 oz. Portland cement (e.g., Lehigh™ Portland Cement        #1 and #2)    -   15 to 20 oz. resin coated sand (e.g., Borden™ shell process        resin coated sand)

The components of the primer layer are mixed together and applied to thesubstrate surface using any appropriate application means, such asbrush, trowel, or spray. Depending upon the size of the batch, curingtime is typically between three to five hours at room temperature. Thiscan be reduced to one to two hours in a controlled heat environment.

The PVA polymer component of the adhesion layer can be sourced fromre-constituted polyvinyl alcohol fibers dissolved in boiling water,preferably distilled water, in an approximate ratio of 16:1. Polyvinylalcohol (PVA) is a reground fiber or waste fiber that is generallyproduced as a by-product in the manufacture of certain medical supplies,such as disposable hospital gowns and hospital bed sheets. As a result,it is an inexpensive material and desirable to use as a recycledmaterial. Polyvinyl alcohol reground fiber, such as is found in theISOLYSER line of products by Orex produced by United Cotton is anexample of an appropriate source of polyvinyl alcohol fibers.Alternatively AIRVOL 125 polyvinyl alcohol can be used in similarconcentrations as that of the recycled PVA fibers.

The PVA catalyst is produced by mixing the dissolved mixture of PVAfibers (the PVA polymer) with Jeffsol® butylene carbonate (made byHuntsman Corp.), in a ratio of 16 parts of PVA polymer to one partbutylene carbonate. This serves to strengthen the PVA catalyst'smolecular bond. An exemplary method of producing a sample size of thePVA catalyst is as follows: boil 16 oz. of distilled water, add 40 gramsof polyvinyl alcohol fibers to the boiling water to produce the PVApolymer, allow the PVA polymer to cool and then add 10-15 cc's ofbutylene carbonate to the mixture. For best results, the PVA fibersshould be completely or nearly completely dissolved in the water beforecooling and adding of the butylene carbonate.

In an alternative embodiment, propylene carbonate can also be usedeither wholly or in part to replace the Jeffsol butylene carbonate. Inthis case, the proportion of propylene carbonate may need to beincreased by about 25% over the stated amount of butylene carbonate.

As shown in the formula provided above, the primer layer also includes asmall amount of Portland cement at about 2% to 3% of volume. ThePortland cement decreases the slickness of the hardened adhesion coatlayer. The combination of Portland cement and sand creates concrete, butin this case without much cement, to provide a rough or gritty surface.

The resin-coated sand represents an aggregate that is added to theprimer/adhesion layer. When used with the PVA catalyst, resin-coatedsand tends to resist absorbing the catalyst. Instead of, or incombination with the resin-coated sand, other aggregates can be used,such as perlite, pumice, vermiculate and man-made pozzalons, and fillitefly ash. Aggregates for use in accordance with the invention areexemplified by a mixture of course and fine relatively inert materials,but may also be of fairly uniform size. Other aggregates that can beused include sand, gravel, silica, glass, crushed stone such as marble,granite, feldspar, basalt, quartz, and so on. However, in a preferredembodiment, resin-coated sand, or other aggregates that exhibit waterand/or oil resistance properties, such as quartz, is used.

To improve the heat dispersion properties of the cementitious veneerpanel, the adhesion layer can also be impregnated with fillers likealuminum hydrate, which is a refractory cement. The aluminum hydrate ismixed with the resin-coated sand to create an adhesion layer thatexhibits pronounced heat dispersion characteristics. The resin-coatedsand can also be mixed with other materials, such as perlite,vermiculite, agricultural or regular pumice, or micro-fiber carbonfibers (such as Thermalgraph™ DXDX). These materials also aid in heatdispersion. If any of these optional materials is used for the adhesionlayer, the amount of sand can be generally be reduced by a correspondingamount. This aids in reducing the weight of the laminate material. Ifperlite is used, it should first be soaked in the polyvinyl polymercomposition, dried and then granulated before it is added to theadhesion layer mixture. This will reduce its tendency to absorb the PVAcatalyst out of the mixture.

In an alternative embodiment of the present invention, the adhesionlayer can be formed using Primus®, which is a material commerciallyavailable from Dryvit Systems, Inc. Primus® is described by themanufacturer as containing 54-62% sand, 26-28% water and 9.9-10.2%acrylic latex polymer/binder.

FIG. 2 is a perspective view of a substrate surface 10 coated with aprimer layer according to the invention. The composition for forming theprimer layer 20 is mixed together to form a liquid. This liquid can beapplied by means including spraying or manual spreading, for exampleusing a brush or trowel. The viscosity of the mixture is dependent uponthe concentration of the polyvinyl alcohol catalyst and aggregate (e.g.,resin-coated sand). The viscosity can therefore be adjusted to optimizeapplication to the surface. For example, if application by spraying isdesired, a relatively low viscosity mixture is prepared. A more viscousmixture can be prepared for manual spreading.

The primer layer mixture is applied to the underlying substrate materialsurface prior to curing and hardening. The mixture is then allowed tocure until hard. The mixture can be applied in amounts sufficient toform a layer having a thickness of between approximately {fraction(1/16)} inch and approximately ½ inch, or any other desired thickness.

In one embodiment of the present invention, the primer layer can includefibers, such as carbon fibers embedded within the layer. This increasesthe fire and heat resistance of the substrate depending upon thethickness of the primer layer and the quantity of added fiber material.It can also increase the strength of the substrate. For improved impactresistance characteristics, materials such as PVA, kevlar, or fiberglasscan be added in fiber or mesh form to the adhesion layer.

Once dry, the primer layer provides a good adhesive surface for thesecond layer (cementitious veneer layer), which is composed primarily ofgypsum cement.

Cementitious Veneer Layer

A cementitious veneer layer 30 is applied to the adhesion layer, asillustrated in FIG. 3, to form the cementitious laminate material. Thisveneer layer provides the look and feel of a concrete or mineral surfaceto the lightweight substrate. In one embodiment of the presentinvention, the cementitious veneer layer 30 comprises a mixture ofmagnesium sulfate, magnesium oxide, filler (e.g., Fillite), gypsumcement, and polyvinyl alcohol catalyst, along with other components. Thetwo basic components of the cementitious veneer layer are a magnesiumoxysulfate composition and a cementitious composition. A more detaileddescription of each of these two components will be provided in thedescription that follows.

The magnesium oxysulfate composition is produced by combining, on avolume basis, 0.04% to 0.08% sodium hexametaphosphate, 0.06% to 0.17%phosphoric acid at a concentration of 75% to 85%, 47% to 54% magnesiumsulfate, 30% to 35% of magnesium oxide, 1.3% to 1.4% distilled water,and 8% to 11% filler (e.g., Fillite).

An exemplary formulation which provides an illustration of the relativepercentages of these ingredients in the magnesium oxysulfate compositionis provided as follows:

-   -   0.20-0.30 oz of sodium hexametaphosphate (sodium        polymetaphosphate)    -   5 cc-15 cc phosphoric acid at a concentration of 75% to 85%.    -   10 oz.-13 oz. magnesium sulfate (e.g., Epsom salts) in fine        powder form    -   3.7 oz-4 oz distilled water    -   8 oz.-10 oz. magnesium oxide    -   3 oz.-5 oz. filler

The sodium hexametaphosphate is a chelating agent which adheresmagnesium sulfate to magnesium oxide. This is preferably added to 3.7 ozof distilled water and blended at low speed for five to ten minutes. Thephosphoric acid acts to dissolve and evenly disperse the sodiumhexametaphosphate throughout the mixture.

As shown above, approximately 8% to 11% filler by volume is added to themagnesium oxysulfate mixture. Fillite 500™ made by Trelleborg FilliteInc. is a preferred ingredient for the filler. For the above exemplarymixture this would correspond to about 4.0 oz of Fillite. Fillite is aninert, hollow silicate sphere, or granular fly ash that acts as anaggregate and increases the strength and water resistance of the veneer.The addition of Fillite also tends to enhance the flow and moldingcharacteristics of the magnesium oxysulfate mixture. The Fillite isadded to the mixture until it is hydrated, and the 10 to 13 oz. ofmagnesium sulfate is added to the hydrated Fillite. To this mixture,about 10 oz. of magnesium oxide is added to create the final magnesiumoxysulfate composition.

With regard to magnesium oxide, Magox™, such as that made by HillsBrothers Chemical is a suitable ingredient for use in the magnesiumoxysulfate composition. Standard grade Magox is suitable, as is grade 83WTG. When combined with the salt, this mixture assumes a liquid elasticconsistency. The mixture is slowly mixed for several hours, which ispossible due to a relatively long curing time.

To the above first mixture of the magnesium oxysulfate composition isadded a second mixture, referred to as the “cementitious composition.”The cementitious composition is produced by mixing together, by volume,1.2% to 1.9% Fillite, 77% to 85% gypsum cement, 13.5% to 14% distilledwater, and 1.25% to 2.5% of PVA catalyst (made by mixing 16:1 polyvinylpolymer and butylene carbonate). An exemplary formulation that providesan illustration of the relative percentages of these ingredients in thesecond mixture is provided as follows:

-   -   0.25 oz Fillite 500, prehydrated with 0.5 oz distilled water    -   11 oz gypsum cement, such as Hydrostone® Super X made by U.S.        Gypsum    -   1.8 oz of distilled water    -   5 cc of PVA catalyst, where the PVA catalyst consists of 40 g of        polyvinyl alcohol fibers boiled in 16 oz distilled water,        cooled, then mixed with 30 cc of butylene carbonate.

The cementitious composition is a polymer layer that features waterproofcharacteristics. The first and second mixtures are combined in thefollowing proportions by weight, two parts first mixture (magnesiumoxysulfate composition) to 3.25 parts second mixture (cementitiouscomposition). That is, by volume, the magnesium oxysulfate compositionshould constitute 61.5% of the combination. In practice, the ratio ofmagnesium oxysulfate composition could range from 37% to 69%, but it hasbeen found that 61.5% is an optimum ratio. The two mixtures are mixedtogether for 5-7 minutes at low speed to produce a semi-liquidcomposition that constitutes the cementitious veneer layer mixture. Thecementitious veneer layer 30 can be applied to the adhesion layer 20 bycommon techniques such as brushing or troweling.

Because magnesium oxide is naturally fire-resistant, the magnesiumoxysulfate within the first mixture imparts a fire-resistantcharacteristic to the cementitious veneer. Likewise, the water-resistantnatural properties of Hydrostone Super X when combined with Fillite inthe second mixture imparts a useful water-resistant characteristic tothe cementitious veneer. The PVA catalyst also aids in water-resistance.

Pigment such as an oxide powder or paste may be added to impart adesired color to the mixture of the cementitious veneer layer 30. Anypigment compatible with cement/gypsum known to those with skill in theart may be used herein.

During the drying period, the surface of the cementitious veneer layermay be ornamentally manipulated by means including embossing with atemplate, pressing, stamping, or carving.

After the cementitious veneer layer has cured it is generally finished,but if desired, it can be further finished by polishing throughtechniques such as wet or dry sanding. The cementitious veneer can becoated on a material which can itself be cut. The cementitious veneerlayer can be cut along with the underlying material. In such case, theveneer layer generally does not chip or scratch, and any rough edges canbe easily polished if desired.

As stated above, the primer layer can include fibers, such as carbonfibers embedded within the layer to increase the fire and heatresistance of the substrate, as well as impact-resistance and strength.Likewise, fibers can also be added to the cementitious layer 30. In oneembodiment of the present invention, fibers added to this layer consistof manufactured Zoltek ½″ chopped fibers B. P. Amoco's ThermalgraphCKDX. Milled fibers, such as Panex 33 MF0200 or Thermalgraph DKDX canalso be used. Poly-vinyl alcohol fibers, such as those made by KurarayCo. can also be used, and are advantageous when used for application inconcrete mixtures, and the RF350×12 mm is a preferable Kuraray fiber.

In an alternative embodiment of the present invention, the distilledwater used in the cementitious veneer layer can be substituted withmicroclustered water produced through a process described in U.S. Pat.No. 5,711,950, or as described in U.S. Pat. No. 6,033,678. Use of suchwater has been found to mix more thoroughly and enhance absorption amongthe ingredients in the cementitious veneer layer. Empirically, use ofmicroclustered water has been found to increase the hardness of thecured cementitious veneer layer by up to 100 percent. When used in thecementitious veneer layer, plastic or ceramic mixing blade and bowlsshould be used when mixing microclustered water, since metal surfacescan negatively impact the crystalline structure of the microclusteredwater molecules.

FIG. 4 illustrates an embodiment of the present invention in whichfibers are embedded within the cementitious veneer layer 40. The surfaceof this layer can be polished so that it is smooth, or it can be leftunpolished to expose the granular pattern of the embedded fibers, as isillustrated in FIG. 4. Prior to curing, the surface of the veneer layer40 can be made to mimic virtually any surface through casting,embossing, or other similar methods. FIG. 5 illustrates an embodiment inwhich fibers are embedded in both the adhesion layer 50 and thecementitious veneer layer 40. The fibers may be carbon fibers or kevlarfibers, glass fibers, or similar types of fibers. For the percentageamounts described above, the amount of fiber used is on the order ofthree to seven grams.

Instead of fibers, other strengthening materials, such as hemp may beadded to either or both of the primer and cementitious veneer layers.For example, industrial hemp fibers available from Kenex Corp. aresuitable types of hemp. To improve mineralization of the reinforcementmaterials, the hemp may be dipped in a lime solution, such as slakedlime and water or alcohol. This serves to calcify the hemp fibers andimproves the texture and uniformity of the cementitious veneer.

In addition to the main formula, other fillers and/or substances can beadded to or substituted in varying percentages in the cementitiousveneer formula to improve hardness, and water and fire resistance. Forexample, aluminum hydroxide is an aggregate that increases andstrengthens the cement matrix of the cementitious composition and isimmune to high heated temperatures. Aggregates by nature increaseporability, which is also true of aluminum hydroxide. Boric acid is amild acid that when mixed with gypsum as well as polyvinyl alcoholcreates stronger compounds. Potassium aluminum is a salt, which acts asan accelerator, hardener and fireproofing aid. When these are usedtogether they tend to cancel each other out therefore providing thebenefit of both without requiring a drying time that is either too fastor too slow. The amounts recommended for the above formula for thecementitious veneer are, 0.20 to 1.00 oz. of aluminum hydroxide, 0.5 to0.20 oz. of boric acid, and 0.5 to 20 oz. of potassium aluminum. Certainmineral aggregates, notably quartz, exhibit advantageous water and oilresistance properties, as well as ornamental properties, that may beadvantageous for use in the cementitious veneer layer.

It should be understood that the embodiments and examples providedherein are for purposes of illustration of the invention. It isenvisioned that those with skill in the art can make modifications tothe embodiments and examples provided herein which are within the scopeand spirit of the invention.

For example, while the above embodiments and examples encompass a first(primer/adhesion) layer and a second (cementitious veneer) layer, it iscontemplated that more than two layers can be applied in accordance withthe present invention. Additional layers of the above described basemixture can be stacked upon each other. Likewise, additional ornamentallayers can be stacked upon each other. Indeed, base layers andornamental layers can be stacked upon each other in alternating fashion.

The composition for the cementitious laminate according to embodimentsof the present invention can be provided as a kit that includes thesubstances required to form the primer layer and the cementitious veneerlayer. Such substances can be pre-mixed, or can be supplied for mixingby the user. The kit can also include containers for mixing and storingthe primer layer and cementitious veneer mixtures, as well as means forapplying the layers to the substrate surface, such as a trowel.

In general, panels or tiles can be formed by coating the substrate withthe adhesion layer and then applying the cementitious veneer layerwithin a mold. The mold can be lined with textured or shaped materialsto impart an ornamental appearance or functional characteristic to thecementitious veneer panel. For example, a course textured mold canimpart a rough or serrated surface that aids in grip or traction for thetile. Likewise, if a glossy finish is desired, the mold can be linedwith a material such as clear vellum. Placing the cementitious veneerlayer in contact with the vellum during the curing step will impart agloss to the panel. Depending upon the type of substrate material used,the cementitious laminate can also be made into sheets similar to theproduction of sheet rock.

In the foregoing, a method for producing a cementitious veneer andlaminate has been described. Although the present invention has beendescribed with reference to specific exemplary embodiments, it will beevident that various modifications and changes may be made to theseembodiments without departing from the broader spirit and scope of theinvention as set forth in the claims. Accordingly, the specification anddrawings are to be regarded in an illustrative rather than a restrictivesense.

1. A structure comprising: a substrate comprising a stiff material; aprimer layer applied to the substrate, the primer layer comprising amixture of polyvinyl alcohol catalyst, Portland cement, and sand; and aveneer layer applied to the primer layer, the veneer layer comprising amixture of magnesium sulfate, filler, magnesium oxide, gypsum cement,and polyvinyl alcohol catalyst.
 2. The structure of claim 1, wherein thesubstrate is selected from the group consisting of cardboard, wood,metal, masonry, fiberglass, gypsum board, plastics, fiberboard, cementfiberboard, and ceramics.
 3. The structure of claim 1, wherein theprimer layer comprises, on a volume basis, 1.5% to 3.6% Portland Cement,68% to 75% resin coated sand, and 29% to 30% polyvinyl alcohol catalystwhich comprises polyvinyl alcohol polymer mixed with butylene carbonatein a ratio of 16:1.
 4. The structure of claim 3, wherein the polyvinylalcohol polymer mixed with butylene carbonate is produced by dissolvingpolyvinyl alcohol fibers in boiling distilled water to form a polyvinylalcohol mixture, and mixing the polyvinyl alcohol mixture with butylenecarbonate, in a ratio of 16 parts of polyvinyl alcohol mixture with onepart butylene carbonate.
 5. The structure of claim 4, wherein the primerlayer is applied to the substrate to form an adhesion layer for theveneer layer, the primer layer having a thickness of betweenapproximately {fraction (1/16)} inch and approximately ½ inch.
 6. Thestructure of claim 1, wherein the veneer layer comprises a first mixtureconsisting primarily of, on a volume basis, 0.04% to 0.08% sodiumhexametaphosphate, 0.06% to 0.17% phosphoric acid at a concentration of75% to 85%, 40% to 46% magnesium sulfate, 30% to 35% magnesium oxide,1.3% to 1.4% distilled water, 2.5% to 3.25% hollow silicate spheres, anda second mixture comprising primarily gypsum cement.
 7. The structure ofclaim 6, wherein the mixture comprises, on volume basis, 1.2% to 1.9%hollow silicate spheres, 77% to 85% gypsum cement, 13.5% to 14%distilled water, and 1.25% to 2.5% of the polyvinyl alcohol catalystwhich comprises a 16:1 mixture of polyvinyl alcohol polymer and butylenecarbonate.
 8. The structure of claim 7, wherein the veneer layer furthercomprises embedded fibers to increase a strength characteristic of thestructure.
 9. The structure of claim 7, wherein the veneer layer furthercomprises pigment or stains to enhance an appearance characteristic ofthe structure.
 10. The structure of claim 7, wherein the veneer layer isornamentally manipulated prior to drying.
 11. The structure of claim 7,wherein the mixture of polyvinyl alcohol polymer and butylene carbonateis produced by dissolving polyvinyl alcohol fibers in boiling distilledwater to form a polyvinyl alcohol mixture, and mixing the polyvinylalcohol mixture with butylene carbonate, in a ratio of 16 parts ofpolyvinyl alcohol mixture with one part butylene carbonate.
 12. Thestructure of claim 11, wherein the first mixture and second mixture arecombined in a ratio of one part first mixture to one and one-half partssecond mixture.
 13. A cementitious laminate comprising: a substratecomprising a stiff material; a primer layer applied to the substrate,the primer layer comprising a mixture of polyvinyl alcohol catalyst,Portland cement, and sand; and a veneer layer applied to the primerlayer, the veneer layer comprising a magnesium oxysulfate compoundincluding magnesium sulfate, magnesium oxide, sodium hexametaphosphate,phosphoric acid, fillers, and water, and a cementitious compositionmixed with the magnesium oxysulfate compound to form a cementitiousveneer mixture, the cementitious composition including gypsum cement,filler, water, and a polyvinyl alcohol catalyst.
 14. The cementitiouslaminate of claim 13, wherein the veneer layer further comprises atleast one member selected from the group consisting of embedded fibersto increase a strength characteristic of the cementitious laminate, andpigment to enhance an appearance characteristic of the cementitiouslaminate.
 15. The cementitious laminate of claim 13, wherein the primerlayer comprises, on a volume basis, 1.5% to 3.6% Portland Cement, 68% to75% resin coated sand, and 29% to 30% polyvinyl alcohol catalyst whichcomprises polyvinyl alcohol polymer mixed with butylene carbonate in aratio of 16:1.
 16. The cementitious laminate of claim 15, wherein theveneer layer comprises a first mixture consisting primarily of, on avolume basis, 0.04% to 0.08% sodium hexametaphosphate, 0.06% to 0.17%phosphoric acid at a concentration of 75% to 85%, 40% to 46% magnesiumsulfate, 30% to 35% magnesium oxide, 1.3% to 1.4% distilled water, 2.5%to 3.25% hollow silicate spheres, and a second mixture comprising, onvolume basis, 1.2% to 1.9% hollow silicate spheres, 77% to 85% gypsumcement, 13.5% to 14% distilled water, and 1.25% to 2.5% of the polyvinylalcohol catalyst which comprises a 16:1 mixture of polyvinyl polymer andbutylene carbonate.
 17. The cementitious laminate of claim 16, whereinthe polyvinyl alcohol catalyst is produced by dissolving polyvinylalcohol fibers in boiling distilled water to form a polyvinyl alcoholmixture, and mixing the polyvinyl alcohol mixture with butylenecarbonate, in a ratio of 16 parts of polyvinyl alcohol mixture with onepart butylene carbonate.
 18. The cementitious laminate claim 17, whereinthe first mixture and second mixture are combined in a ratio of one partfirst mixture to one and one-half parts second mixture.